Not Applicable
The present invention generally relates to bonding systems, and more particularly to an improved bonding system having pressure applicators which transition to and position the repaired/replaced tiles therebetween so that positive and counteracting pressures may be applied to the tiles for proper adhesion.
The outer skins of modern day aircrafts and spacecrafts are typically formed by high-temperature ceramic tiles to protect their underlying structural and electrical parts. By utilizing these tiles, the airplanes and spacecrafts remain quite safe and operable as external elements such as rocks or birds are substantially prevented from damaging their internal parts. However, though such ceramic tiles may achieve their primary objective of protecting the underlying parts, they possess certain deficiencies which detract from their overall utility.
Perhaps the greatest deficiency of the high-temperature ceramic tiles is their susceptibility to impacts caused by the external elements. Such impacts oftentimes result in dents and/or cracks on the outer structural integrity of the aircrafts and spacecrafts. These dents and/or cracks are not only aesthetically unpleasing, but may further lead to undesirable operational characteristics such as reduced aerodynamic characteristics.
Obviously, the marring leading to these structural and operational deficiencies are unacceptable on multi-million dollar aircrafts and spacecrafts. In order to cure such deficiencies, the aircrafts and spacecrafts frequently have to be subjected to multi-step repair procedures. First, the damaged ceramic tiles are taken out as they must be replaced with new ones. Then, the impacted region(s) must be thoroughly cleaned of all dirts and debris. Thereafter, new ceramic tiles are bonded to the impacted region(s) typically with high-temperature silicone adhesives. As is commonly known in the aerospace industry, silicon adhesives require optimal heat and pressure to ensure proper adhesion.
In this respect, especially when the replaced tiles are considerable, the bonded ceramic tiles are typically subjected to vacuum bagging. However, due to tile butt joints and porosity of tiles, such vacuum bagging must extend beyond the replaced tile area. This defined bagging procedure is typically complex, and susceptible to human error if not carefully and meticulously attended to. Furthermore, the vacuum bagging is typically time-consuming, as this procedure may take 8 to 48 hours to accomplish. With the addition of other procedures as mentioned above, the time to repair an aircraft may be extensive, with the greater repair time comes the increased labor costs that the aerospace manufacturing companies must bear.
Thus, there has long been a need in the industry, and in the aerospace industry in particular, for a bonding system which would improve the procedure associated with adhering the replacement ceramic tiles onto aircraft and spacecraft in a more time-efficient and cost-effective manner. Further, there is a need to properly install these ceramic tiles by utilizing a systematic approach to more consistently yield optimal adhesion of the tiles.
The present invention addresses and overcomes the above-described deficiencies of prior art bonding systems by providing an improved bonding system that utilizes its pressure applicators to apply both positive and counteracting pressures upon the repaired/replaced ceramic tiles. More specifically, the pressure applicators themselves transition to the tiles while the tiles are stationed within the bonding system and heated via a removable heating element, so as to conveniently provide both pressure and heat necessary for proper adhesion. In this respect, not only does the present invention mitigate the need to resort to inefficient and costly bond procedures, but it also improves the adhesion that is often required in such procedures.
In accordance with a preferred embodiment of the present invention, there is provided a pressure bonding system for applying pressure onto at least one tile of a workpiece. This system comprises upper and lower gripper members each having first and second gripper ends. The second gripper ends are connected to each other. Further, the first gripper ends are movable relative to each other to receive the workpiece therebetween. Moreover, an upper pressure applicator assembly may be slidably engaged to the upper gripper member. The upper pressure applicator assembly may be slidable along the upper gripper member between the first and second ends along a length of the workpiece. The workpiece may be placed between the upper and lower gripper members with an edge thereof being adjacent the second gripper ends. The upper pressure applicator may apply pressure to the tile(s) upon relative movement of the first ends towards the workpiece to a position adjacent the tile(s).
The upper and lower gripper members may be fabricated from any metallic material. However, aluminum is preferred. Due to the hinged connection of the second gripper ends, the first ends may be movable away from each other to provide an opening which is generally greater than a thickness of the workpiece between the upper and lower gripper members. Preferably, the tile(s) used is ceramic tile(s) which may be bonded to the workpiece such as an aerodynamic structure. An exemplary aerodynamic structure would be a wing of an aircraft.
In accordance with the present invention, a heating element may be disposed between the upper pressure applicator assembly and the tile(s). This heating element is laid over and provides heat to the tile(s) while it is being pressurized. In the preferred embodiment, the heating element used for this purpose is a heat blanket.
The upper gripper member comprises inward and outward gripper surfaces, as well as an exterior side gripper surface forming a channel substantially between the first and second gripper ends. Adjacent to this channel are a series of gripper holes. The upper pressure applicator assembly has a first upper surface which is disposed adjacent the inward gripper surface and which is slidable relative thereto. The first upper surface preferably includes an upper connection bracket that may be slidably engaged to the channel formed along the exterior side gripper surface. This connection bracket has a series of upper connection holes which may be aligned with the gripper holes. When the holes are aligned, a pin may be inserted collectively therethrough to prevent the upper connection bracket, and thus the upper pressure applicator assembly, from further sliding along the channel. Preferably, the upper pressure applicator is a platen having a generally rectangular configuration.
In the present invention, the upper pressure applicator assembly comprises a second upper surface having an upper pressure applicator for applying pressure to the tile(s). More particularly, the second upper surface defines an upper recess in which the upper pressure applicator is disposed therewithin. In one preferred embodiment, the upper pressure applicator may simply be a rubber pad. In the other preferred embodiment, it is a bladder which may be inflated and deflated to apply variable pressure to the tile(s).
In accordance with a preferred embodiment of the present invention, the lower gripper member comprises a lower pressure applicator assembly which is slidably engaged thereto. This assembly is used for counteracting the pressure applied by the upper pressure applicator assembly. Similar to the upper gripper member, the lower gripper member has inward and outward gripper surfaces. It further has an exterior side gripper surface that defines a channel substantially between the first and second gripper ends. A series of gripper holes are formed adjacent to this channel. In the preferred embodiment, the lower pressure applicator assembly is a platen with a generally rectangular configuration.
Furthermore, the lower pressure applicator assembly includes a first lower surface disposed adjacent the inward gripper surface. The first lower surface may be sized and configured to be slidable relative to the inward gripper surface. More particularly, the first lower surface may include a lower connection bracket which may be slidably engaged to the channel formed along the lower gripper member""s exterior side gripper surface. The lower connection bracket defines a series of lower connection holes that may be aligned with the gripper holes whereat a pin may be inserted collectively therethrough. The insertion of the pin in this manner stations the lower connection bracket, and thus the lower pressure applicator assembly, in place.
In addition, the lower pressure applicator assembly may include a second lower surface which has a lower pressure applicator. The lower pressure applicator is utilized for counteracting the pressure applied by the upper pressure applicator assembly. In particular, the second lower surface has a lower recess placing the lower pressure applicator therewithin. Like the upper pressure applicator, the lower pressure applicator may be a rubber pad or an inflatable/deflatable bladder configured to apply variable counteracting pressure.
In accordance with the present invention, a gripper member retaining mechanism may be operatively engaged to upper and lower gripper members to maintain the gripper members in pressure bearing relation to the tile(s). This retaining mechanism is sized to tightly retain the workpiece between the upper and lower gripper members. Although the gripper member retaining mechanism is preferably a manually tightenable clamp, other devices operative to generate compressing force are contemplated. Specifically, the retaining mechanism may be extended between the outward gripper surfaces of the upper and lower gripper members.
In one preferred embodiment of the present invention, the upper gripper member is comprised of first and second elongated upper arms, whereas the lower gripper member is comprised of first and second elongated lower arms. Adjacent or at the second gripper ends, the upper arms each have an upper flange portion and the lower arms each have a lower flange portion. The flange portions of the first upper and lower arms may be generally extended toward and engaged to each other. Likewise, the flange portions of the second upper and lower arms may be generally extended toward and engaged to each other.
More specifically, the upper flange portions may each have an upper aperture and the lower flange portions may each have a lower aperture. In this regard, the lower flange portions may be disposed between the upper flange portions in a manner as to align the lower apertures with the upper apertures. Thereafter, a pivot pin may be inserted through the upper and lower apertures and be secured therewithin so that a hinged connection may be formed thereat.